1. Technical Field
The present invention relates to a projector that includes a light source, an optical modulation device modulating the flux of light emitted from the light source on the basis of image information so as to form an optical image, a projection optical system projecting the formed optical image, and a housing for accommodating the optical modulation device and the projection optical system therein.
2. Related Art
There has been known Projectors each modulate the flux of light emitted from a light source on the basis of image information to form optical images, and magnify and project the optical images onto, for example, a screen.
When driving such a projector, electronic components and optical components constituting the corresponding projector emit heat. Among these electronic components and optical components, some components are easily affected by heat. When the temperature of a heat-sensitive component exceeds the maximum allowable temperature, image formation may not be properly performed. In order to prevent rise in the temperature of a heat-sensitive component, a method of sending air introduced from the outside of the projector to cool the heat-sensitive component can be used.
However, the externally introduced air may contain dust particles. When dust particles enter into the projector, the shades of the dust particles are projected together with optical images so as to deteriorate the images or the dust particles reduce cooling efficiency. In order to prevent infiltration of dust particles, a projector having an sealed space formed therein has been known (see, for example, JP-A-2001-209126).
According to the projector disclosed in JP-A-2001-209126, a sealed space is formed in a housing, and liquid crystal light valves to be cooled and a fan for circulating air in the sealed space are provided in the sealed space. In this projector, air in the sealed space is circulated by rotating the circulating fan, thereby cooling the liquid crystal light valves and dissipating the heat of the heated air from the sealed space.
However, in the projector disclosed in JP-A-2001-209126, since it is needed to form side walls for forming the sealed space in which the liquid crystal light valves to be cooled and the circulating fan are disposed, the inner structure of the housing becomes complicated, which makes the process of manufacturing the projector cumbersome and complicated. For this reason, it is required a technique capable of reliably cooling an object to be cooled in a projector by properly blowing pure air containing no dust.